package PTA.javabianchengjichu2;

import java.util.Scanner;

public class ex23 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

int m = sc.nextInt();
        int s=sc.nextInt();
int d = sc.nextInt();
double result=0;
result = d/1.6/(m*60+s)*3600;
        System.out.printf("%.2f",result);



    }
}
